themes and styles

client/world/drawer.go

@@ -74,6 +74,10 @@ type PrimitiveDrawer interface {
 	// Clear operations must NOT change clip state.
 	ClearAllTo(bg color.Color)
 	ClearRectTo(x, y, w, h int, bg color.Color)
+
+	DrawImage(img image.Image, x, y int)
+
+	DrawImageScaled(img image.Image, x, y, w, h int)
 }
 
 // ggClipRect stores one clip rectangle in canvas pixel coordinates.
@@ -336,3 +340,28 @@ func (d *GGDrawer) ClearRectTo(x, y, w, h int, bg color.Color) {
 		}
 	}
 }
+
+func (g *GGDrawer) DrawImage(img image.Image, x, y int) {
+	g.DC.DrawImage(img, x, y)
+}
+
+func (g *GGDrawer) DrawImageScaled(img image.Image, x, y, w, h int) {
+	if w <= 0 || h <= 0 {
+		return
+	}
+	b := img.Bounds()
+	srcW := b.Dx()
+	srcH := b.Dy()
+	if srcW <= 0 || srcH <= 0 {
+		return
+	}
+
+	g.DC.Push()
+	// Translate to destination top-left.
+	g.DC.Translate(float64(x), float64(y))
+	// Scale so that the source bounds map to (w,h).
+	g.DC.Scale(float64(w)/float64(srcW), float64(h)/float64(srcH))
+	// Draw at origin in the scaled coordinate system.
+	g.DC.DrawImage(img, 0, 0)
+	g.DC.Pop()
+}